Grand piano action



y 5, 1931- G. G. CAMPBELL ET AL 1,803,890

GRAND PIANO ACTION Fil ed Oct. 17, 1930 X 6916 e a ac;

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20.6 fil Egx pacm 0 Eww Patented May 5, 1931 UNITED STATES PATENT OFFICE GORDON CAMPBELL, OF UPPER MONTOLAIR, AND JOSEPH KLEPAC, OF FORT LEE, NEW, JERSEY, A SSIGNORS T KOI-ILER-BRAMBACH PIANO COMPANY, OF NEW YORK,

' N. at, A CORPORATION on NEW YORK GRAND PIANO ACTION 'Application filed October 17, 1930. Serial No. 489,414.

This invention relates to the action mecha nism of a grand piano by which blows are struck on the strings.

It is the-general object of our invention to simplify the construction of a grand piano action, reducingthe number of parts and greatly decreasing the cost of manufacture. A further object is to provide a construction in which springs are entirely omitted and in which resetting of the jacks for repetition is effected by a positive cam action. I

' An important feature of our invention relates to the provision of an improved and simplified. damper mechanism.

Our invention further relates to arrangements and combinations of parts which will be hereinafterdescribed and more particularly pointed out in the appended claims.

A preferred form of the invention is shown in the drawings, in which Fig. 1 is a sectional side elevation of a grand piano action; and

Figs. 2, 3 and 4 are fragmentary side elevations showing certain parts in different operative relations.

Referring to the drawings, we have shown a portion of a grand piano action comprising a key loosely pivoted on a fixed pin or stud 11 and guided by a second pin or stud 12. A whip or lever 14: is mounted on a fixed pivot 15 and is provided with a pad or cushion 16 engaged'by a capstan screw 17 threaded into the key 10.

A jack 20 is pivotally connected at 21 to the whip 14 and is provided with an offset arm 22 normally resting on a felt button 23 on the upper face of the whip 14. As the whip and jack approach their upper limit of travel, the arm 22 engages the head of a stop screw 25, threaded into a flange 26 formed on the whip rail 27 A hammer 30 is provided with a butt 31 pivoted at 32 on a fixed rail The butt 31 has a recess 35 in its lower face, adapted to receive the narrowed upper end 36 of the jack 20. The end 36 ispreferably cushioned with a layer 37 of thin leather or other suitable material.

The walls of the recess 35 are of special conformation for purposes to be described. The upper wall of the recess is provided with a shoulder i0 and notch 41. The right hand wall of the recess, as viewed in the drawings, is provided with an inclined stop surface 42, and the left hand wall of the recess is shaped to provide a cam surface 43.

iVhen the parts are at rest, the end 36 of the jack 20 is postioned under the shoulder 40, as shown in Fig. 1, being held in this position by engagement of the cam face 13 with the upper end 36 of the jack. As the key is depressed and the parts approach their upper limit of travel, the arm 22 of the jack engages the stop screw 25, as shown in Fig. 2, and the jack is shifted from the shoulder 40 to the notch 41, as indicated in Fig. 3, thus allowing the hammer to drop back slightly from the strings and preventing a damping effect.

As pressure on the key 10 is relieved, the hammer 30 and hammer butt 31 swing downward to the position shown in Fig. 4-, causing the cam face 43 to engage the upper end 36 of the jack 20 and to reset the ack unc er the shoulder 40, restoring the parts to the position shown in Fig. 1. This re-setting action takes place when the key 10 has moved upward about half way to its original position. The action is thus well adapted to rapid repetition, which is much valued by professional pianists.

It should be particularly noted that the jack is re-set by the positive cam action of the cam face 43 and that there are no springs of any sort included in the action, whereas the more common and well known actions now in use almost invariably use at least two springs for the return of the parts to initial relation.

A further feature of our invention relates to an improved and simplified damper mechanism.

In carrying out this feature of our improvements, we mount a damper on a rod 51 slidable vertically in bearings 52 and 53. At its lower end, the rod 51 is provided with a block 54: positioned for engagement by a projection 55 at the rear end of the key 10. A pin 56 is mounted in the block 54 and extends freely upward through a second guiding openingin the. lower bearing 53. The pin 56 thus prevents angular movement of the rod 51 and damper 50. The block 54 is of such weight as to produce the desired damping effect when the damper rests upon the string S.

For the loud pedal effect, a rail is provided which is hinged to a fixed upright member 61 and is provided with a projecting portion 62 underlying the blocks 54. The rail 60 may be swung forward and upward by any suitable mechanism, thus causing the projection 62 to engage and lift all of the dampers 50.

One form of lifting mechanism is indicated in the drawings and comprises an arm 63 extending downward from the rail 60 and positioned for engagement by a bell crank 64- actuated through a lifter rod 65 from the usual damper pedal of a grand piano.

From the above description, it will be seen that both the hammer actuating mechanism and the damping mechanism of our i1nproved action is greatly simplified over the present commercial structures, with corresponding reduction in cost of manufacture.

Furthermore, the omssion of springs greatly simplifies the assembling of the mechanism and there is practically no adjustment required, so that the ,me of setting an action in a piano is very substantially reduced.

Having thus described our invention and the advantages thereof, we do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what we claim is r 1. In a grand piano action, a key, a whip actuated thereby, a jack pivoted to said whip, a hammer having a butt engaged by said jack, means to release the jack from the hammer as the jack approaches its upper limit of travel, and means to re-set the jack by the weight of I the hammer.

2. In a grand piano action, a key, a whip actuated thereby, a ack pivoted to said whip, a hammer having a bu t engaged by said jack, means to release the jack from the hammer as the jack approaches its upper limit of travel, and cam means'acting positively on said ack to re-set the same.

3. In a grand piano action, a key, a whip actuated thereby, a jack pivoted to said whip, a hammer having a butt engaged by said jack, means to release the jack from the hammer as the jack approaches its upper limit of travel, and cam means formed on the hammer butt and acting positively on said jack to re-set the same. 7

4. In a grand piano action, a key, a whip actuated thereby, a jack pivoted to said whip, a hammer having a butt engaged by said jack, means to release the jack from the hammer as the jack approaches its upper limit of travel, and cam means fo "med on the hammerbutt and through which the weight of the hammer acts on said jack as the hammer swings downward and forces said jack into operative lifting relation with said hammer butt.

5. In a grand piano action, a key, a whip actuated thereby, a jack pivoted to said whip, a hammer having a butt provided with a recess to receive the upper end of said jack, the upper end of said recess comprising a shoulder and a notch, and one side of said recess comprising a cam face adapted to engage the end of said jack as the hammer swings downward and to thereby force the jack out of the notch and under the shoulder.

G. In a grand piano action, a damper, a lifter rod therefor, a block fixed to the lower end of said rod, a guide wire mounted in said block, guiding bearings for said rod and wire, and means to give said block a direct upward movement.

7. In a grand piano action, a damper, a lifter rod therefor, a block fixed to the lower end of said rod, a guide wire mounted in said block, guiding bearings for said rod and wire, means to give said block a direct upward movement, a rail extending across the action, means to swing said rail, and means on said rail for directly engaging and lifting all of said hammer blocks.

In testimony whereof we have hereunto affixed our signatures.

GORDON G. CAMPBELL. JOSEPH KLEPAC. 

